What the heck is IBU?

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

andylegate

Well-Known Member
Joined
Aug 14, 2006
Messages
100
Reaction score
0
Location
Aiken, SC
Being new to homebrewing I have no idea what a IBU is. I went and explored the free tools at Beertools.com (cool site) and punched in the stuff for my batch I'm making. It even told me how much it should have cost me to make it! And it was close!
But it said this batch will have a bitterness of 8.8% IBU (on a scale of 0 - 100 %). So first off, what is IBU, and how bitter is 8.8%?
Cheers!
Andy
 
It's a measurement of bitterness. It's not a percentage of anything. You can only really taste up to about 100 IBUs, although there are some recipes that produce beers with IBUs in excess of that (for various reasons). 8.8 really isn't bitter at all, that's less bitter than BMC. What kind of beer are you making?
 
This batch that the beertools said would have an 8.8% IBU is the Chocolate Cherry recipie that I got from here. I just punched in the Carmel Cream recipie that I'm also going to be brewing on Monday or Tuesday and it came out with a 19.6% IBU. The 2nd recipie has 3 kinds of hops (Cascade, Tenag, Saaz) with the cascade being boiled the full 60 minutes. I am assuming here that the higher bitterness level is due to the cascade hops being boiled the whole 60 minutes, or am I wrong about that?
 
Pretty much every beer recipe I've seen calls for at least one of the hops to be boiled the full 60 minutes. Remember, though, it's not just the number of hop types or the total amount, it also depends on the alpha acide % of the hops used. You will usually see the percentage listed in paratheses. A high-alpha hop like Chinook will lend a lot more bitterness than something with a lower AA%, like Fuggles.

As Dude will attest with his 278.8 IBU Pliny (yes, I was thinking of you), there's a lot more to hops than just bitterness.

As the to amount of time in the boil, hops boiled for the full 60 minute duration are going to provide the background bitterness. VIrtually all of the flavor oils and aroma oils will be boiled away over that time, just leaving the bitterness. Hops boiled for shorter periods of time will have less of an impact on overall bitterness, but will provide more flavor and aroma. Hops added at the very end of the boil - or in the secondary fermenter ("dry hopping") just provide some aroma.

Is that Cheesefood's Caramel Cream ale that you're doing, or another recipe? If you haven't look at Cheesefoods', it has a phenomenal reputation (I haven't made it yet myself). One thing that he has run into (and I ran into on a batch of my own) is that these kinds of beers, with lots of extra fruits and hops and sweetness, can sometimes lose a little bit of their beer character. Just something to be aware of, both beers sound like they will definately be on the sweet side, hopefully with some good malty character.

DUDE: I'd love a Pliny, you up for a swap? My bastardization of Walker's IPA needs two weeks, or I'd be happy to pick you up some local micros if you wanted to sample something GOOD!
 
yep, it's Cheesefood's recipie. The Carmel Cream that is. I'm going to brew it on tuesday. I'm going to modify the recipie just a little bit and see how it comes out. After these two, I'm going to make a American Pilsner as per my wife's request. She's into much lighter beers.
The Chocolate cherry that's fermenting now, I did modify the recipie and waited to add the hops until the last 15 minutes of boil. It used 6 lbs of Dark Malt Extract liquid. I also didn't do the grains the same. Rather I used what grains were called for, but instead of placing them in the water and bringing the water up to boil, (that's what the recipe called for), I heated and held the water steady at 160 F and steeped the grains for 30 minutes instead. Over all the wort is extreemly dark in color and smells great with both chocolate and malt.
 
andylegate said:
This batch that the beertools said would have an 8.8% IBU is the Chocolate Cherry recipie that I got from here. I just punched in the Carmel Cream recipie that I'm also going to be brewing on Monday or Tuesday and it came out with a 19.6% IBU. The 2nd recipie has 3 kinds of hops (Cascade, Tenag, Saaz) with the cascade being boiled the full 60 minutes. I am assuming here that the higher bitterness level is due to the cascade hops being boiled the whole 60 minutes, or am I wrong about that?


Are you sure you're not talking about Alpha Acids? Cuz hops are rated in Alpha Acids which is a percentage of acids in the hops, and therefore presented as a percentage. Meanwhile, IBU's are UNITS, not percentages. They are a unit of bitterness present in the finished beer. Clear as Mother's Milk, right?:mug:
 
andylegate said:
The Chocolate cherry that's fermenting now, I did modify the recipie and waited to add the hops until the last 15 minutes of boil.

This could be a little bit of a problem. If the recipe called for these to be bittering hops (60 minute boil) rather than flavoring hops (15 minutes), you won't have as much base bitterness as the recipe calls for, while the actual flavor of the hops competes with the chocolate and the cherries. The advice that I got on a recent brew (a mocha stout) was basically to keep the hops out of the way, i.e. use a fair amount for bittering but don't use flavoring or aroma hops as the floral characteristics don't usually work well with chocolate. In general, you don't want to screw around too much with the hops schedule.

But hey, it could be great, and it'll certainly be beer! Good luck with it.
 
They list the IBU on Beertools.com in percentages.

I posted elsewhere on here: I sampled the batch while changing out the fermentor lid. Most of the activity has stopped. The brew has the clarity of a Yahoo chocolate soda! And tastes like one too! Except you can taste the other ingredients too. I'll finish it of course and we'll see what happens.
 
andylegate said:
They list the IBU on Beertools.com in percentages.
I'm sure that's just a simple mistake in the software. I think someone else mentioned rather emphatically that IBUs are not percentages, but just arbitrary units...which is exactly what they are - a simple way of trying to quantify bitter flavors. 10 IBUs is really mild, 30 is pronounced, 50 is pretty d*mn bitter, and anything over 100 almost qualifies as ridiculous, but not impossible (which it would be if IBU were presented as a percentage figure).
 
I was reading on the internet and may add a little more light.... or maybee need to go drink more beer to add to the haze... either way here it is...

"This brings up a good question, how bitter is bitter? Well, in terms of IBUs, 20 to 40 is considered to be the typical international range. North American light beers, like Coorsú, have a bitterness of only 10-15 IBUs. More bitter imported light beers, like Heinekenú, have a bitterness closer to 20-25. American microbrews like Samuel Adam Boston Lagerú have a bitterness of about 30 IBUs. Strong bitter ales like Anchor Liberty Aleú and Sierra Nevada Celebration Aleú have bitterness of 45 or more.
While more experimentation and analysis needs to be done to accurately predict hop bittering potential, the IBU equations described on the next page have become the common standard by which most homebrewers calculate the final bitterness in the beer. Everyone who uses these equations is in the same ballpark and that is close enough for comparison." Ch 5.4 How to brew by J. Palmer http://www.howtobrew.com/section1/chapter5-4.html

too much time on my hands..... :tank: :mug:
 
Back
Top